1. Field of the Invention
The present invention relates to a bare chip carrier which is used in an electrical test of semiconductor bare chips, and more specifically to electrical connection of the bare chip carrier.
2. Description of the Background Art
When a semiconductor bare chip (hereafter simply referred to as “a bare chip”) diced from a semiconductor wafer is to be shipped as it is as a product, the bare chip must undergo electrical tests (also called electrical measurements) using semiconductor test system such as an IC tester or a burn-in system.
At this time, a bare chip carrier is used for mounting the above-described bare chip on an IC socket on a testing board used in the IC tester or on a burn-in board used in the burn-in system. That is, the bare chip carrier that holds the bare chip is mounted on the IC socket to conduct various electrical tests.
A conventional bare chip carrier will be described below.
FIG. 6 is a cross-sectional view for illustrating a conventional bare chip carrier.
As shown in FIG. 6, the bare chip carrier comprises a bare chip carrier base member (hereafter simply referred to as a base member) 1, and a bump electrode 3 for electrically connecting the base member 1 with a pad electrode 21 of a bare chip 2. Furthermore, the bare chip carrier comprises a bare chip carrier lid 6 for fixing the bare chip 2 on the base member 1, an insulating film 7 for electrically insulating the bare chip 2 from a wiring 9, a bare chip carrier electrode 8 for connecting the bare chip carrier to an external IC socket, and the wiring 9 for connecting the bare chip carrier electrode 8 with the bump electrode 3.
Here, the bare chip carrier electrode 8 and the wiring 9 are integrally formed of an electrically conductive film. In other words, an electrically conductive film is used as a bare chip carrier electrode in the above-described conventional bare chip carrier.
However, the electrically conductive film has a problem that the mechanical strength is low, and deformation, such as warping or bending, occurs easily. Therefore, there is a problem that defective contact occurs between the bare chip carrier electrode 8 and a connecting terminal (e.g., a contactor described later) of the IC socket connected to the electrode 8.
As a countermeasure for this problem, a bare chip carrier electrode is directly formed on the base member in the bare chip carrier disclosed in Japanese Patent Laid-Open No. 10-213626. According to this bare chip carrier, the stability of contact between the connecting terminal of the IC socket and the bare chip carrier electrode is maintained without being affected by deformation such as warping or bending.
The Specification also discloses that a bump electrode similar to the one used in semiconductor devices of the BGA structure is formed on the bare chip carrier electrode to correspond to a burn-in socket for BGA.
In the above-described prior art, however, nothing has been devised regarding the structure of electrodes used in the bare chip carrier. Conventionally, a pad electrode, a bump electrode, or the like has been used as the bare chip carrier electrode. In other words, a well-known electrode used in a semiconductor device has simply been used as the bare chip carrier electrode.
In recent years, when electrical tests are conducted, high electrical and mechanical contact is required between an IC socket and a bare chip carrier.
However, high electrical and mechanical contact cannot be achieved in the structure of conventional bare chip carrier electrodes.